THE PELAGIC ENVIRONMENT OF THE OPEN OCEAN
75
is progressive reduction in reliance on vision with
increasing depths (Hiller-Adams and Case, 1988), nonvisually hunting species might be expected to show
only temperature-related reductions in metabolic rates.
There are some limited physiological data available
for gelatinous plankton which support this hypothesis
(Childress and Mickel, 1985; Thuesen and Childress,
1993b, 1994). Childress and Thuesen (1992) drew up
a speculative budget for metabolic carbon flux for
the oceanic Pacific (Table 3.5). They derived a total
global estimate of oceanic biomass to be 8.7 gigatons
wet weight of which 3% was benthic and 20% was
benthopelagic. The total annual respiratory flux they
derived was 5.4 gigatons C (10
15 g), of which just 0.4%
was benthopelagic and 9% benthic.
Thus many of the characteristics of pelagic species
and communities that were originally inferred from
observations of their bathymetric profiles are being
confirmed and improved upon as a result of improved
techniques of sampling and measuring living organisms. One important conclusion to be drawn from these
new insights is that the tendency for modellers to treat
midwater processes as “black boxes” in drawing up
chemical budgets is fraught with dangers. If large-scale
and long-term changes are indeed being induced by
natural and anthropogenic changes in climate, there
may be substantial impacts on processes within the
water column of the deep ocean that have significant
positive or negative feed-back effects on deep-ocean
budgets, which may well cause some surprises.
REFERENCES
Angel, M.V., 1983. A vertical profile of planktonic ostracods at 42ºN
17ºW from depths of 1500–3900 m. In: R.F. Maddocks (Editor),
Applications of Ostracoda. University of Houston, Geoscience
Department, pp. 529–548.
Angel, M.V., 1984. The diurnal migrations and distributions of a
mesopelagic community in the North-east Atlantic. 3. Planktonic
ostracods, a stable component in the community. Prog. Oceanogr.,
13: 319−351.
Angel, M.V., 1989a. Does mesopelagic biology affect the vertical
flux? In: W.H. Berger, V.S. Smetacek and G. Wefer (Editors),
Productivity of the Oceans: Past and Present. Wiley, New York,
pp. 155–173.
Angel, M.V., 1989b. Vertical profiles of pelagic communities in the
vicinity of the Azores Front and their implications to deep ocean
ecology. Prog. Oceanogr., 22: 1−46.
Angel, M.V., 1990. Life in the benthic boundary layer: connections
to the mid-water and sea floor. Philos. Trans. R. Soc. London Ser.
A, 331: 15−28.
Angel, M.V., 1993. Biodiversity of the pelagic ocean. Biol.
Conservation, 7: 760−772.
Angel, M.V., 1997. Pelagic biodiversity. In: R.F.G. Ormond, J. Gage
and M.V. Angel (Editors), Marine Biodiversity: Patterns and
Processes. Cambridge University Press, pp. 35–68.
Angel, M.V. and Baker, A. de C., 1982. Vertical standing crop
of plankton and micronekton at three stations in the North-east
Atlantic. Biol. Oceanogr., 2: 1−30.
Angel, M.V. and Pugh, P.R., 2000. Quantification of diel vertical
migration by micronektonic taxa in the Northeast Atlantic.
Hydrobiologia, 440: 161−179.
Angel, M.V., Hargreaves, P., Kirkpatrick, P. and Domanski, P.A.,
1982. Low variability in planktonic and micronekonic populations
at 1000 m depth in the vicinity of 42ºN 17ºW; evidence against diel
migratory behaviour in the majority of species. Biol. Oceanogr.,
1: 287−319.
Backus, R.H., 1986. Biogeographical boundaries in the open ocean.
UNESCO Tech. Pap. Mar. Sci., 49: 9−13.
Barange, M. and Pillar, S.C., 1992. Cross-shelf circulation, zonation
and maintenance mechanisms of Nyctiphanes capensis and
Euphausia hanseni (Euphausiacea) in the northern Benguela
Upwelling system. Continental Shelf Res., 12: 1027−1042.
Billett, D.S.M., 1991. Deep-sea holothurians. Oceanogr. Mar. Biol.
Annu. Rev., 29: 259−317.
Billett, D.S.M., Lampitt, R.S., Rice, A.L. and Mantoura, R.F.C., 1983.
Seasonal sedimentation of phytoplankton to the deep-sea benthos.
Nature London, 302: 520−522.
Billett, D.S.M., Hansen, B. and Huggett, Q.J., 1985. Pelagic
Holothuroidea (Echinodermata) of the northeastern Atlantic.
In: B.F. Keegan and D.S. O’Connor (Editors), Echinodermata.
Balkema, Rotterdam, pp. 399–411.
Bone, Q., Marshall, N.B. and Blaxter, J.H.S., 1995. Biology of Fishes,
2nd Edition. Blackie Academic and Professional, London, 332 pp.
Bouchet, P. and Taviani, M., 1992. The Mediterranean deep-sea
fauna: pseudopopulations of Atlantic species? Deep-Sea Res., 39:
169−184.
Bouchet, P. and War´ en, A., 1985. Revision of the Northeast
Atlantic bathyal and abyssal Aclididae, Eulimidae and Epitoniidae
(Mollusca, Gastropoda). Boll. Malacol., 2: 297−576.
Bowmaker, J.K., Dartnall, H.J.A. and Herring, P.J., 1988. Long-wavesensitive visual pigments in some deep-sea fishes: segregation of
‘paired’ rhodopsins and porphyropsins. J. Comp. Physiol., 163A:
685−698.
Brewer, P.G., Glover, D.M., Goyet, C.M. and Shafer, D.K., 1995.
The pH of the North Atlantic Ocean: improvements to the global
model for sound absorption in seawater. J. Geophys. Res., 100(C5):
8761−8776.
Broecker, W.S., 1992. The great ocean conveyor. In: B.G. Livi, D.
Afemeister and R. Scribner (Editors), Global Warming: Physics
and Facts. American Institute of Physics, New York, pp. 129–161.
Cherry, R.D. and Heyraud, M., 1981. Polonium-210 content of marine
shrimp: variation with biological and environmental factors. Mar.
Biol., 65: 165−175.
Childress, J.J., 1975. The respiratory rates of midwater crustaceans
as a function of depth occurrence and relation to the oxygen
minimum layer off Southern California. Comp. Biochem. Physiol.,
50A: 787−799.
Childress, J.J. and Mickel, T.J., 1985. Metabolic rates of animals from
the hydrothermal vents and other deep-sea habitats. Bull. Biol. Soc.
Washington, 6: 249−260.
Childress, J.J. and Price, M.H., 1978. Growth rate of the bathypelagic
75
is progressive reduction in reliance on vision with
increasing depths (Hiller-Adams and Case, 1988), nonvisually hunting species might be expected to show
only temperature-related reductions in metabolic rates.
There are some limited physiological data available
for gelatinous plankton which support this hypothesis
(Childress and Mickel, 1985; Thuesen and Childress,
1993b, 1994). Childress and Thuesen (1992) drew up
a speculative budget for metabolic carbon flux for
the oceanic Pacific (Table 3.5). They derived a total
global estimate of oceanic biomass to be 8.7 gigatons
wet weight of which 3% was benthic and 20% was
benthopelagic. The total annual respiratory flux they
derived was 5.4 gigatons C (10
15 g), of which just 0.4%
was benthopelagic and 9% benthic.
Thus many of the characteristics of pelagic species
and communities that were originally inferred from
observations of their bathymetric profiles are being
confirmed and improved upon as a result of improved
techniques of sampling and measuring living organisms. One important conclusion to be drawn from these
new insights is that the tendency for modellers to treat
midwater processes as “black boxes” in drawing up
chemical budgets is fraught with dangers. If large-scale
and long-term changes are indeed being induced by
natural and anthropogenic changes in climate, there
may be substantial impacts on processes within the
water column of the deep ocean that have significant
positive or negative feed-back effects on deep-ocean
budgets, which may well cause some surprises.
REFERENCES
Angel, M.V., 1983. A vertical profile of planktonic ostracods at 42ºN
17ºW from depths of 1500–3900 m. In: R.F. Maddocks (Editor),
Applications of Ostracoda. University of Houston, Geoscience
Department, pp. 529–548.
Angel, M.V., 1984. The diurnal migrations and distributions of a
mesopelagic community in the North-east Atlantic. 3. Planktonic
ostracods, a stable component in the community. Prog. Oceanogr.,
13: 319−351.
Angel, M.V., 1989a. Does mesopelagic biology affect the vertical
flux? In: W.H. Berger, V.S. Smetacek and G. Wefer (Editors),
Productivity of the Oceans: Past and Present. Wiley, New York,
pp. 155–173.
Angel, M.V., 1989b. Vertical profiles of pelagic communities in the
vicinity of the Azores Front and their implications to deep ocean
ecology. Prog. Oceanogr., 22: 1−46.
Angel, M.V., 1990. Life in the benthic boundary layer: connections
to the mid-water and sea floor. Philos. Trans. R. Soc. London Ser.
A, 331: 15−28.
Angel, M.V., 1993. Biodiversity of the pelagic ocean. Biol.
Conservation, 7: 760−772.
Angel, M.V., 1997. Pelagic biodiversity. In: R.F.G. Ormond, J. Gage
and M.V. Angel (Editors), Marine Biodiversity: Patterns and
Processes. Cambridge University Press, pp. 35–68.
Angel, M.V. and Baker, A. de C., 1982. Vertical standing crop
of plankton and micronekton at three stations in the North-east
Atlantic. Biol. Oceanogr., 2: 1−30.
Angel, M.V. and Pugh, P.R., 2000. Quantification of diel vertical
migration by micronektonic taxa in the Northeast Atlantic.
Hydrobiologia, 440: 161−179.
Angel, M.V., Hargreaves, P., Kirkpatrick, P. and Domanski, P.A.,
1982. Low variability in planktonic and micronekonic populations
at 1000 m depth in the vicinity of 42ºN 17ºW; evidence against diel
migratory behaviour in the majority of species. Biol. Oceanogr.,
1: 287−319.
Backus, R.H., 1986. Biogeographical boundaries in the open ocean.
UNESCO Tech. Pap. Mar. Sci., 49: 9−13.
Barange, M. and Pillar, S.C., 1992. Cross-shelf circulation, zonation
and maintenance mechanisms of Nyctiphanes capensis and
Euphausia hanseni (Euphausiacea) in the northern Benguela
Upwelling system. Continental Shelf Res., 12: 1027−1042.
Billett, D.S.M., 1991. Deep-sea holothurians. Oceanogr. Mar. Biol.
Annu. Rev., 29: 259−317.
Billett, D.S.M., Lampitt, R.S., Rice, A.L. and Mantoura, R.F.C., 1983.
Seasonal sedimentation of phytoplankton to the deep-sea benthos.
Nature London, 302: 520−522.
Billett, D.S.M., Hansen, B. and Huggett, Q.J., 1985. Pelagic
Holothuroidea (Echinodermata) of the northeastern Atlantic.
In: B.F. Keegan and D.S. O’Connor (Editors), Echinodermata.
Balkema, Rotterdam, pp. 399–411.
Bone, Q., Marshall, N.B. and Blaxter, J.H.S., 1995. Biology of Fishes,
2nd Edition. Blackie Academic and Professional, London, 332 pp.
Bouchet, P. and Taviani, M., 1992. The Mediterranean deep-sea
fauna: pseudopopulations of Atlantic species? Deep-Sea Res., 39:
169−184.
Bouchet, P. and War´ en, A., 1985. Revision of the Northeast
Atlantic bathyal and abyssal Aclididae, Eulimidae and Epitoniidae
(Mollusca, Gastropoda). Boll. Malacol., 2: 297−576.
Bowmaker, J.K., Dartnall, H.J.A. and Herring, P.J., 1988. Long-wavesensitive visual pigments in some deep-sea fishes: segregation of
‘paired’ rhodopsins and porphyropsins. J. Comp. Physiol., 163A:
685−698.
Brewer, P.G., Glover, D.M., Goyet, C.M. and Shafer, D.K., 1995.
The pH of the North Atlantic Ocean: improvements to the global
model for sound absorption in seawater. J. Geophys. Res., 100(C5):
8761−8776.
Broecker, W.S., 1992. The great ocean conveyor. In: B.G. Livi, D.
Afemeister and R. Scribner (Editors), Global Warming: Physics
and Facts. American Institute of Physics, New York, pp. 129–161.
Cherry, R.D. and Heyraud, M., 1981. Polonium-210 content of marine
shrimp: variation with biological and environmental factors. Mar.
Biol., 65: 165−175.
Childress, J.J., 1975. The respiratory rates of midwater crustaceans
as a function of depth occurrence and relation to the oxygen
minimum layer off Southern California. Comp. Biochem. Physiol.,
50A: 787−799.
Childress, J.J. and Mickel, T.J., 1985. Metabolic rates of animals from
the hydrothermal vents and other deep-sea habitats. Bull. Biol. Soc.
Washington, 6: 249−260.
Childress, J.J. and Price, M.H., 1978. Growth rate of the bathypelagic